Disposal of waste by incineration

ABSTRACT

Waste is disposed of by incineration including burning solids, vaporizing liquids and converting any residual gases into elemental substantially odorless form. Discharge temperature of the treated gases is reduced to an acceptable level. Practice of the method is exemplified in an incineration apparatus such as a toilet utilizing a &#39;&#39;&#39;&#39;soft&#39;&#39;&#39;&#39; gas flame providing not only incinerating and vaporizing heat within a firebox but also gas consuming heat in a combustion passage leading from the firebox. Circulation of the products of combustion is promoted by an exhaust fan which draws them across a cooling air gap into a settling chamber before discharge from the apparatus. Various operating and safety structures and controls are provided.

United States Patent 1191 1111 3,827,378 Kufrin et al. [45] A 6, 1974 [54] DISPOSAL OF WASTE BY INCINERATION 3,230,913 l/ 1966 LaMere 4/131 X 75 Inventors: Frederick w. Kufrin, .lanesville; 33:22:11;

Paul Vimoche, Newton; Donald 3,323,473 6/1967 Frankel J. llen, For Atk nson; l p 3,357.3s1 12/1967 Stevens 110/9 Gokey, Whitewater; Frederick A. 3,413,659 12/1968 Nordstedt et al. 110 9 x Rose, Fort Atkinson, all of Wis.

Primary ExaminerKenneth W. Sprague [73] Asslgnee' 52 wave Company sheboygan' Attorney, Agent, or Firm-Hil1, Sherman, Mcroni,

Gross & Simpson [22] Filed: May 22, 1972 [2]] Appl. No.: 256,776 ABSTRACT App'icam" $33? v a ilfiifi fi fiiil"ilb l iifllillfi'ill 2113121 [62] Division 2 2 3 201319 March gases into eleme nta l substantially odorliss f orm. Dis- Pat. No. 3, charge temtserlaturle 3f the treatild gasels is reduced to 53 1. 110/9 g 4g1/i; g3g gg g gyj igggi i g ig g g li iiiigllflj [58] Field assi n11111111111111111'1in/9"n59 E; 5/131; gg g g 5 g"? immersing n va OI'lZlIlg ea w1 in a ire ox u a so gas con- 307/88'5 317/1485 suming heat in a combustion passage leading from the firebox. Circulation of the products of combustion is [56] References cued promoted by an exhaust fan which draws them across UNITED STATES PATENTS a cooling air gap into a settling chamber before dis- 2,477,632 8/1949 Liebmann 110/9 charge from the apparatus. Various operating and 2,835,215 5/1958 Harm 110/9 afety structures and ontrols are provided, 2,903.709 9/1959 Blankenship et a1. 110/9 x 3.103.017 9 1953 LaMere 4/131 23 Clam, 10 Drawmg Figures PATENTED RUG 51974 SHEEI 1 0F 7 PATENTED A115 6 74 SHEEY 2 UF 7 PATENIED 51974 SHEET 3 [If 7 l I l l I I lllculnlllllllll'l II I I J. n l -l l b- PATENTEBAUB slam] SHEET 0F 7 WENFEMB 61974 SHEET 6 OF 7 This a division, of application Ser. No. 20,319, filed Mar. 17, 1970, now Pat. No. 3,694,825, dated Oct. 3, 1972.

This invention relates to disposal of waste by incineration, and is more particularly concerned with a method and apparatus suitable for an incinerator toilet.

A major problem with incinerators, and especially incinerator toilets, has been the emission of noxious odors resulting from incomplete combustion or at least failure to reduce vapors to eliminate gases. It is, of course, necessary or at least highly desirable to effect incineration as rapidly as possible. In small incinerators such as toilets, space is generally limited, apparatus must be as simple and foolproof as possible, and economy both in the initial cost and in operation must be considered, in order to be practical for the intended purpose. To this end, it has heretofore been proposed to collect the waste material in a sump-like receptacle and drive a blow-torch-like flame generally downwardly thereagainst. Whereas this does accomplish rapid incineration within a relatively limited space or firebox, it has the disadvantage of merely vaporizing liquid constituents of the waste material with odorous discharge or exhaust.

According to the present invention, the foregoing and other disadvantages, shortcomings, inefficiencies and problems are overcome by the new and improved disposal method and means disclosed herein.

An important object of the present invention is to provide a new and improved method of for disposing of waste by incineration in a novel, rapid, efficient and safe manner.

Another object of theinvention is to provide for the complete and efficient incineration of waste material in a manner to provide odorless exhaust.

A further object of the invention is to provide a new and improved method of for incineration utilizing a soft flame such as provided by an atmospheric burner.

Still another object of the invention is to provide new and improved incineration methods.

Yet another object of the invention is to provide a new and improved method for incineration disposal of waste including solids and liquids including superheating vapors to eliminate odors.

A yet further object of the invention is to provide new and improved method enabling practice in a compact efficient incinerator toilet apparatus liquidified with operating and safety controls therefor.

Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:

FIG. 1 is a perspective view of an incinerator in the form of a toilet and embodying features of the invention;

FIG. 2 is a schematic illustration showing the manner in which combustion is effected;

FIG. 3 is a vertical sectional detail view taken substantially along the line IIIIII of FIG. 1;

FIG. 4 is an enlarged vertical sectional detail view taken substantially along the line lV-IV of FIG. 3;

FIG. 5 is a sectional plan view taken substantially along the line V-V of FIG. 3;

FIG. 6 is a perspective view looking downwardly and rearwardly into the incinerator toilet with the top closure removed;

FIG. 7 is amore or less schematic top plan view similar to FIG. 5 but showing a modification;

FIG. 8 is a fragmentary elevational view taken substantially along the irregular line VIlI-Vlll of FIG. 5;

FIG. 9 is an enlarged fragmentary sectional elevational view taken sustantially along the line IX-IX of FIG. 5; and

FIG. 10 is an electrical schematic of the operating and control circuitry for the apparatus.

In accordance with the principles of the present invention, waste materials including solids and liquids are subjected to soft flame, i.e., such as that produced by an atmospheric burner in which combustible gas such as propane under ordinary tank pressure is released through a burner nozzle within which it is mixed with air at atmospheric pressure and ignited and the flame as thus produced utilized for incineration. Maximum exposure of the waste material to the flame is effected to attain thorough incineration of solids and evaporation of liquids, and the vapors are then superheated, causing breakdown of the vapors into elemental gases to eliminate odors. Finally, the odorless products of combustion are cooled by mixing ambient air therewith and exhausted to atmosphere. This method is particularly useful for incinerator toilets.

By way of example of apparatus in and by which the method is adapted to be practiced, an incinerator toilet (FIG. 1) is shown which includes an outer housing 15 having a base 17 and an upper closure 18 which is removably supported on a lateral supporting ledge flange 19. In the top of the closure 18 is a suitable opening 20 (FIGS. 3 and 4) within which is suspended a removably supported funnel-like toilet bowl 21 having an upper out-turned marginal supporting rim flange 22 which engages on the closure 18 about the opening 20. Over the bowl opening is mounted a toilet seat 23 and a cover 24 therefor both hingedly connected at the rear of the assembly to swing between open and closed positions about the axis of a shaft 25 rotatably mounted on a supporting bracket structure 27 carried by the closure 18. For selective independent or joint raising and lowering of the seat and cover, the seat 23 is mounted by means of respective left and right brackets 28 which are freely pivotally connected to left and right mounting brackets 29 which are rigidly connected to the ends of the shaft 25 as by means of respective couplings 30. Through this arrangement the cover 24 may be raised from the seat 23 as desired, and the seat 23 may be raised from the bowl rim 22 for whatever purpose desired such as for removing the bowl 21 for cleaning.

At its lower funnel end, the bowl 21 has a discharge opening 31 aligned with the opening in the seat 23, and disposed to discharge into a combustion or incinerating chamber 32 provided by means of an upwardly opening box-like fire pot or chest 33 suitably supported permanently or removably, as preferred, in the lower portion of the cabinet housing 15 and spaced from the outer walls of the cabinet housing adequately to provide for the interposition of proper heat insulation to avoid any objectionable transfer of heat from the combustion chamber or firebox to the outer wall of the cabinet.

Any objectionable upward escape of heat from within the firebox chamber 32 is avoided by upper end closure means therefor comprising a fire door structure desirably in the form of a pair of separable heat insulated fire doors 34 which are complementary in size to each other, and each over about half of the top opening into the combustion chamber. To enable convenient separation of the tire doors 34 when access into the chamber 32 is desired, they have end margins extending beyond opposite ends of the chest structure 33 and supported slidably on respective tracks provided by means comprising rails 35 carried by the upper end portions of the end walls of the chest.

Means are provided for automatically opening the fire doors 34 when the lid or cover 24 is swung open and for returning the fire doors to the combustion chamber closing relationship when the cover 24 is returned to the closed downward position. To this end, the couplings 30, which are co-rotative with the shaft 25, desirably provide respective operating cams 37 projecting rearwardly thereon and facing downwardly and adapted to be engaged by means of follower rollers 38 of motion transmission means comprising respective vertically extending plunger rods 39 which are desirably square in cross section and are vertically reciprocably slidably supported by and between vertically spaced rearwardly projecting horizontally extending flanges 40 of a transverse bracket bar 41 which they may comprise a frame bar within and secured to the inner walls of the upper rear portion of the cabinet 15. Normally the plungers 39 are biased upwardly by means comprising respective coiled compression springs 42 engaged thereabout, having their lower ends bottomed on the lower bracket flange 40 and thrusting upwardly against respective shoulder flanges 43 fixed on the plungers. This causes the follower rollers 38 on the upper ends of the plungers normally to engage and follow the associated cams 37. Conversion of vertically reciprocal motion of the plungers 39 into respective opening and closing movements of the fire doors 34 is effected by means of respective racks 44 on the plungers 39 above the shoulders 43 meshing with respective pinions 45 co-rotative with respective rock shafts 47 rotatably journalled on and between the bracket frame bar 41 and a transverse bracket frame bar 48 within and across the upper front portion of the cabinet 15. Operating connection between the respective shaft 47 and the fire door sections 34 is effected by means of a pair of angular crank arms 49 rigidly attached to each of the shafts 47 and each pair of the arms having respective coaxial terminal end portion journals 50 engaged in suitable bearings 57 mounted on the outer side edges of the associated fire doors. Through this arrangement, as the seat cover 24 is raised, the cams 37 act through the followers 38 to depress the plungers 39 against the biasing springs 42 and thereby through the racks 44 rotate the respective pinions 45 and thereby the shafts 47 to swing the crank arms 49 sidewardly as shown in dot-dash outline in FIG. 4 and in full outline in FIG. 6, whereby to pull the respective door sections 34 into open position wherein their inner edges are adequately clear of the discharge opening 31 from the bowl 21. Swinging of the cover 24 to closed position results in corresponding return of the fire door sections 34 to the closed position by action of the biasing springs 42 which were compressed and loaded incident to downward thrusting of the plungers 39 when the COVCI' was open.

Incinerating flame is introduced into the combustion nozzle 52 having its tip projected through a suitable opening 53 in the rear wall of the firebox chest 33. Preferably, the nozzle 52 is of the venturi mixing atmospheric burner type leading from an atmospheric air intake 52a(FIGS. 2 and 3) through which combustible gas is delivered by way of a duct 54 leading from a gas valve assembly 55 by way of which gas is supplied from a supply duct 57 located in the rear lower portion of the housing 15. An ignitor 58 is associated with the flame tip of the nozzle 52. In the preferred arrangement, the flame issuing from nozzle 52 is of the soft type comprising fuel gas such as propane, natural gas, or any other preferred combustible gas supplied to the nozzle 52 under ordinary line or tank pressure and mixed with the atmospheric air through the mixer 52a so that instead of a jet or blowtorch-like flame propelled with substantial velocity, the flame will issue into the chamber 32 in a manner to enable it substantially to fill the chamber. To enhance such filling of the chamber, narrow divergent deflector blades 59 (FIGS. 2, 3, 5 and 6) are mounted adjacently in front of the discharge end of the nozzle 52. In addition, secondary air for improving combustion is adapted to enter th chamber 32 about the nozzle 52 through the opening 53 in the chamber wall.

Within the combustion chamber 32, material to be incinerated is exposed to the flame in the most efficient manner. That is, solids are substantially enveloped in the flame and liquids separate from the solids are evaporated not only by heat from the top, but also heat applied thereunder from the flame issuing from the nozzle 52. Efficiency in this respect is enhanced by receiving solids on an elevated grid or grate 60 desirably in the form of a perforated plate having preferably integral therewith depending coextensive opposite side supporting leg flanges 61, desirably also perforated and removably supporting the grate in and over a liquid collecting evaporating sump pan 62. As best seen in FIG. 3, at its front and rear edges, the grate plate 60 desirably has relatively divergently downwardly oblique respective narrow deflector flanges 63. Further, the plate 60 is desirably located above the upper edge of the pan 62 and is supported at an elevation about level with a horizontal axis on which the nozzle 52 is preferably located. Thereby flame from the nozzle 52 will efficiently envelop solid material M (FIG. 2) on the plate 60 not only above, but also below through the perforations in the plate. Evaporation of liquids in the pan 62 is enhanced by diverting flame from the rear of the pan downwardly thereunder along a downwardly and forwardly sloping rear wall 64 which diverts some of the flame under the pan which is supported above the bottom of the chamber 32 as by means of bar brackets 65 and 67 to afford clearance under the pan. In addition, although the pan may be dimensioned to occupy space from side-to-side within the box 33, as best seen in FIG. 5, it is spaced not only from the rear wall of the box sufficiently to enable travel of heating flame therebeneath, but it is also spaced from the front wall for a good flue action between the front of the pan and the front wall of the box so that the flame heat from below the pan can readily join the flame heat, products of combustion and vapors through an exit opening 68 in the front wall of the box, aligned generally with the grate plate 60.

Operating temperature in the combustion chamber 32 is great enough to consume the material M and vaporize the fluids, and vapor and the products of combustion leave through the opening 68. If directly discharged to atmosphere this effluvium would be detectable by its odor. Means are therefore provided for superheating the vapors to break them down into elemental gases and eliminate odor before discharging to atmosphere. In a simple, efficient arrangement, such superheating is effected in a chamber 69 into and through which all of the products of combustion and vapors must pass as a confined stream from the outlet 68. In the simplest arrangement, the chamber 69 is provided within a duct 70 desirably horizontally along the front wall of the firebox 33 and then continuing angularly rearwardly along a side wall of the firebox. For this purpose, the duct 70 may be simply a sheet metal structure secured directly to the walls of the firebox 33 and in fact utilizing the associated area portions of the firebox walls as part of the duct wall structure. Thereby, not only is heat within the duct 69 derived from the continuing burning of gas and air started in the combustion chamber 32 and continuing through the outlet 68 and in the duct, but also by heat transmitted through the sheet metal wall of the firebox 33 and added to the heat directly circulated into the duct. This subjects the vapors in the duct to superheating, on the order of l,0OOF. so that by the time the stream has advanced through the chamber 69 to an exit extension 71 (FIGS. 5 and 9) of the duct 70, the stream will consist only of elemental gases and any slight incombustible fly ash that may be entrained therein.

At the extension 71, the gases are too hot to permit safe discharge to atmosphere. Accordingly, means are provided for rapidly cooling the gases, in this instance accomplished by mixing therewith a large volume of atmospheric air as the gases are drawn across a substantial air gap 72 between the discharge end of the extension 71 and a mixing and settling chamber 73 provided in a vertically elongated box-like housing 74 preferably of generally rectangular form and having adjacent to but spaced above a bottom end thereof in a wall spaced from the end of the extension 71 an inlet opening 75 aligned with and of preferably larger size than the outlet end of the extension. For drawing the hot gases and cooling air into the chamber 73, suction is applied to draw the cool gas and air mixture from the mixing chamber 73 through an exit opening 77 located in the upper portion of one of the vertical walls of the box casing 74. As the air and gas mixture turns to move upwardly from the entrance or inlet opening 75 to the outlet 77, fly ash or other solids entrained therein drop to the bottom or collecting floor of the casing within the chamber 73. Exhaust suction is applied through the opening 77 by suitable means such as a fan which may be of the squirrel cage type rotatably mounted within a housing 78 and driven by a motor 79. An exhaust duct 80 may lead from the fan housing 78 directly to atmosphere or to a stack, as preferred. For clean-out purposes, the mixing chamber box or casing 74 is desirably removably mounted, as best seen in FIGS. 8 and 9, as by means of studs 18 engageable in upwardly opening vertical slots 82 in respective hanger brackets 83 secured to the blower casing 78 to receive the mixing chamber casing 74 therebetween. Support for the blower casing 78, and thereby the mixing chamber casing 74, is desirably provided by a bracket 84 carried by the cabinet housing 15 in the upper rear portion thereof. Normally covering the mixing chamber and blower is a hood 85 on the rear portion of the closure 18 and which may be permanently attached to or separable from the closure 18 as preferred but in any event removable for access to the area rearwardly from the seat and firebox area of the housing for servicing and clean-out purposes.

Inasmuch as the mixing chamber 73 is within the housing 15, the blower induced draft thereinto serves to ventilate the interior of the housing during use. While incineration is proceeding, the ventilating action not only draws ambient cooling air into the housing through various openings, but also withdraws heated air from within the housing, thereby supplementing the heat insulation in and about the housing walls in maintaining the exterior surfaces of the housing cool.

Where for any reason, such as heavier loads, unusually large volume of liquid waste, frequent use, and the like, larger volumes of vapor are produced or liable to be produced in the combustion chamber 32 than may efficiently be superheated in the superheating chamber 69 by the heat produced by the primary flame introduced by the nozzle 52, additional heat may be supplied to the second or superheating chamber 69 by after-burner means as indicated in FIG. 7. For this purpose, the duct 70 is desirably provided with a lead-in section 87 which may conveniently be provided as an angular integral portion of the duct mounted on the opposite side of the fire box 33 from that along which the lead-out portion of the duct extends to the terminal portion 71. An open entrance 88 into the duct portion 87 permits combustion-promoting air to enter about a gas flame nozzle 89 serving as a secondary or afterburner to project into the duct flame having a B.T.U. capacity when mixed with the air entering through the entrance opening 88 to supplement the heat derived from the primary burner through the firebox exit opening 68 to superheat the vapors sufficiently to convert them into primary gases free from odor. If preferred, of course, electrically energized heating means may be provided, but generally a gas flame to supply the additional heat may be found more convenient, especially where the primary flame is supplied by gaseous fuel.

In order to insure safe and efficient operation of the incinerator toilet described above, it is provided with an electrical control circuit for monitoring and controlling the operation thereof. A monitoring circuit for this purpose is exemplified in FIG. 10 as comprising a pair of input terminals and 101 for connection to a conventional electrical supply, for example volts AC at 60 Hz. Terminal 100 is connected to one terminal of a primary winding 108 of a step-down transformer 107 over a series path including a fuse 102, a normally closed switch 103 and a switch contact 104 engaged with a switch contact 105. The terminal 101 is connected to the other terminal of winding 108 over a series path including a switch contact 109 which is engaged with a switch contact 110. The voltage is therefore stepped down at a secondary winding 112 of the transformer 107 whereupon it is impressed across a bridge rectifier 116 over a first path including a switch contact 113 in engagement with a switch contact 114, and over a second path including a switch contact 117 in engagement with a switch contact 118. The bridge rectifier 116 includes a plurality of diodesl20-l23 which are connected for full-wave rectification of the alternating wave. A pair of diodes 121 and 122 have their anodes commonly connected and in turn connected to ground while another pair of diodes 120 and 123 have their cathodes commonly connected, and in turn connected by way of a conductor 124 to a normally closed switch 130 which is utilized to signal positive box replacement.

The resistor 131 is serially connected to ground by way of a capacitor 132 and is connected to the cathode of a zener diode 134 by way of a resistor 133. Inasmuch as it was found advantageous in a working embodiment of the invention to employ integrated circuits, in one case for example the Motorola MC 7400 P, which requires 4.7 volts DC for operation, the resistors 131 and 133 and the capacitor 132 and the zener diode 134 provide a filter regulator having an output voltage +V of 4.7 volts DC. Of course, other circuits and voltages could be employed as required or desired.

Attention is invited at this point that the switch 103 performs an interlock function and is mounted at the rear upper portion of the outer housing (FIG. 6) and includes an operating plunger 103a for operational engagement with the top closure 18. It should also be pointed out that the switch 125 (FIG. 9) is mounted at the extension 71 to sense the temperature of the elemental gases passing thereby. This thermostat switch is rated at a temperature of approximately 1,400F and will operate to open the powering connection to the control circuit and the burner upon detection of excessive exhaust temperature. This thermostat must be manually reset before the unit may again be operated, reset being effected by depression of the push-button 128.

The aforementioned integrated circuits include, and other circuits may realize, a plurality of dual input positive NAND gates for controlling the operation of the incinerator toilet. In the circuit illustrated herein a first pair of such gates 135 and 136 are connected in a wellknown manner to form a set-reset multivibrator. Another pair of dual gates 137 and 138 are also connected to form a set-reset multivibrator. The gate 135 has an output 139 connected to an input 141 of the gate 136. Likewise, the gate 138 has an output 142 connected to an input 144 of the gate 137.

When power is applied, a pair of capacitors 153a and 191a hold their respective sides of the multivibrators (outputs 153 and 191, respectively) at the power supply level momentarily, thereby forcing the multivibrators into the desired initial state. In this state, the output 139 and the input 141 of the gates 135 and 136 respective are at the high level. Accordingly, an input 145 to a gate 146 is placed at a high level, another input 147 of the gate already being at a high level by virtue of its connection to the supply +V over a resistor 148. The gate 146 includes an output 149 which is therefore at a low level. The output 149 is connected to the base of a transistor 151 by way of a resistor 150. The transistor 151 has its emitter connected to a base of a transistor 152 and its collector connected in common with the collector of the transistor 152. The emitter of the transistor 152 is connected to ground and its collector is returned to the DC voltage at conductor 129, in this case 12 volts DC, by way of the motor 79. The low level at the output 149 of the gate 146 is therefore ineffective to render the transistors 151 and 152 conductive. The motor 79 is therefore not energized.

The gate 136 has an output 153 which is connected to an input 154 of the gate 135. At this time in the operational sequence the output 153 is at a low level and this low level is connected to an input 155 of a gate 157. Similarly, the high level at the output 142 of the gate 138 is connected to an input 156 of the gate 157. With a high level at the input 156 and a low level at the input 155, the gate 157 is effective at an output 158 at a high level. The output 158 of the gate 157 is connected to an input 159 of a gate 161. The gate 161 includes a further input 160 which is connected to the supply +V by way of a resistor 62. The gate 161 includes an output 163 which is effective at a low level due to the high level at its inputs 159 and 160. The output 163 is connected by way of a resistor 164 to the base of a transistor 165 connected to a Darlington configuration with a second transistor 1650. The low level at the output 163 is ineffective to render the transistors 165 and 165a conductive at this time.

The transistors 165 and 165a are connected in circuit with the burner circuit of the incinerator toilet. At the present time in the sequence the motor 79 is not operating to provide a flow of air and the burner is not yet operated.

The first step in the operating sequence is initiated by the application of power or the previous opening of the fire doors 34, which will be explained in detail below, whereby the +V potential at the collector of a transistor 212 is impressed on an input 167 of the gate 136 as a pluse and effects a change of state of the multivibrator so that the output 139 goes to a low level and the output 153 goes to a high level. The resulting low level at the input 145 of the gate 146 renders the gate 146 effective at a high level at its output 149, which in turn renders the transistors 151 and 152 conductive to provide an energizing path for the motor 79. The motor 79 is therefore energized and an air flow is established by way of the blower apparatus. The establishment of air flow is sensed by a sail switch 230 which is disposed on the blower casing 78 (FIG. 9) and includes a vane 231 remotely coupled to a contact which 232. Closure of the switch 230 therefore verifies air flow.

The high level now present at the output 153 of the gate 136 is effective at the input 155 of the gate 157 to shift the output 158 thereof to a low level. In turn, this low level is effective at the input 159 of the gate 161 to render the gate 161 operable at a high level at its output 163. The high level at the output 163 is effective over the resistor 164 to render the transistors 165 and 165a conductive. The transistors 165 and 165a do not, however, render the burner unit operative in that the cover 24 is still raised and the fire doors 34 are open; hence, power is not yet available to the burner unit.

The control circuit will remain in the status last discussed and nothing further will happen until the toilet cover 24 is lowered. The lowering of the cover 24 is effective as discussed above to close the fire doors 34. One of the tire doors has a switch 168 associated therewith and mounted on the transverse bracket frame bar 48. The switch 168 includes an operating plunger 169 for operation upon closure of the corresponding fire door 34 by a protruding portion 170 of the respective shaft 47. The other fire door has a switch 171 similarly associated therewith and mounted on the transverse bracket frame bar 48 and includes a plunger 172 for operation by a protruding portion 173 of the respective shaft 47. The switches 168 and 171 are electrically connected in series in the burner circuit to insure complete closure of both fire doors 34 before ignition and operation of the burner.

The burner includes two solenoid valve to allow for modulation of input. A first of these is not illustrated herein but is effective between the collector of the transistor 165 and the junction 176. The modulating one of the valves is represented by the winding 175 in series with a 950F thermostat 177 which is physically disposed on the exhaust exit extension 71 (FIG. 9). Upon closure of the switches 168 and 171 by operation of the fire doors 34, a relay, preferably a reed relay, including a winding 172 is energized to close its contacts 173 associated with the ignitor circuit 174. Closure of the contact 173 effects a voltage divider including a resistor 175, a contact 177 engaged by a contact 176, the switch 173, a contact 179 in engagement with a contact 180 and a resistor 182 across the commercial supply. One terminal of the resistor 182 is connected to the gate electrode of a silicon controlled rectifier 183 for energization of the ignitor 174 to provide ingition at the gap 184.

The circuit includes a flame proven switch 185 having a flame sensor 186 (FIG. 3) and opens upon the detection of an adequate flame to deenergize the relay winding 172 and open the contacts 173 thereof and deenergize the ignitor 174.

The electrical circuit of the blower further includes a l50F flame blow back switch 187 (FIG. 3) disposed above and behind the opening 53 and connected in series with the fire door switches 168, 171 and the solenoid valves of the burner. This switch is normally closed and operative upon an adverse draft condition to prevent a sustained flame of reverse direction.

Also, the electrical circuit of the blower includes a normally closed, thermally operated and manually resettable switch 125 (FIG. 9) in series with the switch 187. The switch includes contacts 126 and 127 which part at a predetermined temperature, say 1,350F., to protect against excessive heat or thermal overload of the apparatus. A reset button is provided to reclose the contacts 126 and 127.

At room temperature, the 950F. thermostat 177 is closed causing the burner to operate at maximum heat input, for example 30,000 Btu hr, until the temperature at this thermostat is sensed to be 950F. At this temperature, the thermostat contacts open to deenergize the winding 175 and decrease the heat input to a lower level, for example 25,000 Btu, hr.

During normal burn operation, temperatures in the unit remain constant until all waste materials are gone, that is, disposed of by the heat input. Thereupon, the heat input is automatically discontinued responsive to detected temperature variance in the enclosure of the unit. To this end, when all waste material is gone temperatures rise rapidly and at 1l50l200F. contacts of a thermostat switch 188 close to place ground potential, the low level, on an input 189 of the gate 137. Previously the input 189 was maintained at the potential of the supply +V by way of a resistor 190. The gate 137 includes an output 191 connected to an input 192 of the gate 138. The low level placed on the input 189 by the thermostat switch 188 reverses the state of the multivibrator 137, 138 so that the input 142 of the gate 138, and hence, the input 156 of the gate 157 are at a high level. Since the input remains at a low level, the output 158 is at a high level. A high level at the input and at the input 159 of the gate 161 placesa low level at the output 163 to render the transistor non-conductive. The burner unit is therefore deenergized by the effective open circuit at the non-conducting transistor 165. The motor 79, however, continues to run to exhaust air and initiate cooling of enclosure within the incinerator toilct. Thereby, maximum efficiency, with minimum fuel and power expenditure are attained because the control system automatically responds to waste load disposal requirements, i.e. short duration for small loads and proportionally larger duration for larger loads.

As the unit cools down to a temperature of 150F. contacts of a limit thermostat 193 close to place a low level signal on an input 194 of the gate 135. Previously the input 194 was maintained at the supply voltage by way of a resistor 195 connected to the supply +V. The low level now applied to the input 194 is derived over a resistor 196 having a capacitor 197 connected in shunt therewith. The closure of the contacts of the limit thermostat 193 also places a low level on an input 198 of the gate 138 by way of a diode 199. The input 198 was previously maintained at the potential of the supply +V by way of a resistor 200. The grounding of the inputs 194 and 198 resets both multivibrators to effect a low level at the output 149 of the gate 146 to render the transistors 151 and 152 non-conductive. The motor 79 is therefore deenergized and ceases to operate.

The energy remaining the the rotating motor upon deenergization is dissipated by way of a diode 201 and a resistor 202 connected in shunt with the motor 79. This energy discharge path prevents a reverse voltage building up across the transistors 151 and 152. Upon deenergization of the motor the incinerator toilet is ready for the next cycle of operation.

If operation is interrupted during the incinerating cycle at any time by raising the cover 24, the tire doors 34 are opened and the switches 168 and 171 are opened to deenergize a voltage divider comprising a resistor 203 and a resistor 204 and therefore place an input 205 of a gate 206 at a low level or gound potential. A capacitor 204a across the resistor 204 serves to smooth the ripple due to the fuel wave rectified supply. The gate 206 includes a second input 207 which is maintained at the supply potential +V by way of a resistor 208. The gate 206 further includes an output 209 which jumps to a high level upon the opening of either or both of the switches 168 and 171. The output 209 is connected to the base of a transistor 212 by way of a capacitor 210 and the base of the transistor 212 is further connected to ground by way of a resistor 211. The capacitor 210 and the resistor 211 form a differentiator to differentiate the voltage change at the output 209 into a pulse for rendering the transistor 212 momentarily conductive. This same operation is also effective in opening the fire doors to utilize the toilet whereby the voltage shift at the elements 201205 is translated into a setting pulse at the collector of the transistor 212.

Conduction of the transistor 212 momentarily places the input 198 of the gate 138 at ground or low level potential and insures that the state of the multivibrator 137, 138 is proper for restarting the sequence regardless of the time during the cycle at which the cover 24 was opened. The collector of the transistor 212 is connected to the diode 199 which prevents resetting of the multivibrator 135, 136 and subsequent deenergizationv of the motor 79 due to the momentary grounding of the input 198. The same diode 199, however, as previously explained, permits the multivibrator 137, 138 to be reset along with the multivibrator 135, 136 by the action of 150F. thermostat 193.

A plurality of capacitors 167a, 189a and 194a have been provided to suppress transient at the respective inputs 167, 189 and 194 of gates 136, 137 and 135. Also, attention is invited that the switch 193 is not connected directly to ground, but utilizes a shunt connected resistor and capacitor, inasmuch as the contacts of the switch 193 remain closed until temperatures in the incinerator toilet rise. If the input 194 were connected directly to ground during this condition, the multivibrator would not change waste when the cover switch 166 was closed. When the 150F. limit switch 193 opens, the resistor 196 is employed for the purpose of discharging the capacitor 197 so it will be ready for the next closing of the contacts.

Attention is again directed to the left-hand portion of the circuit illustrated in FIG. 10. Although the circuit has been described for operation from a commercial alternating supply, the circuit is also operable from a conventional direct current supply such as a 12 volt battery. For operation on direct current, the circuit is provided with a switch or changeable terminal strip represented by the contacts 104-106, 109-111, 113-115, 117-119 and 177-181, all of which have been previously pointed out. In addition the switch or terminal strip further includes contacts 213-218. These switch contacts are illustrated as they would be engaged for AC operation: for DC operation their opposite engagement is effected.

In DC operation a suitable supply is connected to the input terminals 100 and 101. The terminal 101 is connected to a reference, here ground, by way of closed contacts 109 and 111. The terminal 100, however, is connected to the switch 125 by way of the fuse 102, the interlock switch 103, and contacts 104 and 106. The direct current potential necessary for operation of the gates and transistors is therefore made available directly from the external supply. The ignition circuit is, however, modified for DC operation. in order to provide the necessary high voltage for reliable ignition at the gap 184, means are provided for generating the required voltage. To this end, an oscillator inverter is provided comprisin a transistor 220, the transformer 107, a resistor 221, a resistor 222, and a capacitor 223.

Upon a demand for ignition and the corresponding closure of the relay contacts 173, the base of the transistor 219 is connected by way of a resistor 224 and switch contacts 181, 179, 173, 176, 178, 106, 104 and switch 103 and fuse 102 to the input terminal 100. The transistor 219 is therefore rendered conductive and establishes a path to ground for the emitter of the transistor 220 by way of the winding 112 and the contacts 117 and 119. Also, the direct current potential is further applied to the collector of the transistor 220 by way of the conductor 225, the conductor 124 and the contacts 218 and 216. The same potential is applied to the base of the transistor 220 by way of the resistor 221 and the emitter of the transistor 220 is further connected to the base of the transistor by way of the winding 112 the switch contacts 113, and 115 and the resistor 221. The transistor 220 is therefore rendered operative in an oscillatory mode wherein the previously designated secondary winding 112 is now effective as a primary winding and the previously designated primary winding 103 is effective as a secondary winding, the switch contacts 213 and 215 being effective to place the capacitor 223 across the winding 108 and'across the ignitor 174. The left-hand portion of the winding 112 and the resistor 221 effect a positive feedback for the transistor 220 to sustain oscillations. Attention is especially invited to the fact that the transformer 107 is being employed in this instance as a step-up transformer; whereas, in AC operation it was employed as a step-down transformer. The application of the required high level alternating voltage across the ignitor 174 energizes the ignitor to provide the necessary spark at the gap 184. At this point the burner ignites and the flame sensor 186 operates to open the switch and deenergize the winding 172. Deenergization of the winding 172 opens the contact 173 to remove the enabling bias for the transistor 219 and turn off the oscillator.

Generally then, an incinerator toilet that is both efficient and safe has been set forth in an exemplary embodiment which may be controlled by connection to either AC or DC electrical supplies.

Of course, many changes and modifications of the invention may be become apparent to those skilled in the art without departing from the true spirit and scope of the invention, and it is to be understood that we wish to include within the patent warranted hereon all such changes and modifications as may be reasonably and properly included within the scope of our contribution to the art.

We claim as our invention:

1. A method of waste disposal such as in an incinerator toilet, comprising:

supporting solid waste material on a grate separate from and above liquid waste; and

directing flame from an atmospheric burner operating on ordinary line or tank pressure mixed with atmospheric air toward one edge of the grate to envelop it and the solid material thereon both thereabove and therebelow and to evaporate the liquid waste by heat from the flame below the grate.

2. A method according to claim 1, including providing the incinerating and vaporizing heat by substan tially filling a grate enclosing combustion chamber with soft flame.

3. A method according to claim 1, including cooling the odorless gases before exhausting them to atmosphere.

4. A method according to claim 1, including mixing the odorless gases with cooling air and then exhausting the cool mixture to atmosphere.

5. A method according to claim 1, including drawing said odorless gases and cooling air into a mixing chamber, and exhausting the mixture from the mixing chamher.

6. A method according to claim 1, comprising issuing the flame from a nozzle horizontally aligned in spaced relation to said edge of the grate.

7. A method according to claim 1, wherein said grate and burner are located within a tire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, and conducting the flame and products of combustion and vapor through an opening in said wall into a superheating chamber.

8. A method according to claim 1, wherein said grate and burner are located within a fire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, conducting the flame and products of combustion and vapor through an opening in said wall into a superheating chamber, and in said chamber controlling the temperature in a range of 950F. to 1,200F. for rendering the gases odorless to the human sense of smell before exhausting such gases to atmosphere.

9. A method according to claim 1, wherein said grate and burner are located within a fire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, conducting the flame and products of combustion and vapor through an opening in said wall into a superheating chamber, and in said chamber maintaining a temperature on the order of 1,000F.

10. A method according to claim 1, wherein said grate and burner are operatively located in respect to a combustion and vaporizing first chamber having a wall and duct means of substantial length extending along said wall to provide a second chamber contiguous and in heat-exchange relation throughout most of its length to said first chamber, conducting products of combustion and vapor from the first chamber through said second chamber duct means, and in said second chamber superheating the products of combustion and vapor into odorless gases.

11. A method according to claim 1, including deflecting part of the flame from the burner to more upwardly onto the grate and the material thereon, and deflecting part of the flame to move under the grate.

12. A method according to claim 1, wherein said grate and burner are operatively located in respect to a combustion and vaporizing first chamber having a wall and duct means of substantial length extending along said wall and providing a second chamber contiguous and in heat-exchange relation throughout most of its length to said first chamber, conducting products of combustion and vapor from the first chamber through said second chamber duct means, in said second chamber superheating the products of combustion and vapor into odorless gases, and receiving the gases from the duct means in a mixing chamber and therein mixing the gases with cooling air before release to atmosphere.

13. A method of waste disposal such as in an incinerating toilet, comprising:

depositing solid waste material on a grate;

collecting liquid waste in a receptacle below the grate;

mixing air with fuel at ordinary line or tank pressure and producing flame thereby from an atmospheric burner; and

directing flame from the burner toward one edge of the grate to envelop it and the material thereon both thereabove and therebelow with the flame and evaporating the liquid waste in the receptacle by heat from the flame below the grate.

14. A method according to claim 13, including conducting products of combustion and vapor through a superheating chamber and therein converting the products of combustion and vapor to odorless gases, mixing the odorless gases with cooling air, and exhausting the cooled odorless gases to atmosphere.

15. A method according to claim 13, including conducting products of combustion and vapor through a superheating chamber and therein converting the products of combustion and vapor to odorless gases, introducing heat in addition to heat derived from said burner into said chamber to accelerate superheating of the products of combustion and vapors, mixing the odorless gases with cooling air, and exhausting the cooled odorless gases to atmosphere.

16. A method according to claim 13, including conducting products of combustion and vapors through a duct chamber and therein superheating and converting the same into odorless gases, and controlling said burner in response to temperature variance detected in respect to said duct chamber.

17. A method of waste disposal such as in an incinerator toilet including an upwardly opening housing and an upwardly opening fire pot mounted within a lower portion of the housing, with means for directing material downwardly into the fire pot, comprising:

moving a pair of fire door from a closed edge-to-edge position from between said fire pot and an upper portion of said housing into spaced apart position, depositing material to be incinerated into the fire pot with said fire doors in the spaced apart position;

moving said fire doors into closed edge-to-edge position;

operating heat-producing means to incinerate the material in the fire pot, and

electrically controlling said heat-producing means by said fire doors individually to become inoperative when the doors are open and operative only both of when the doors are completely closed.

18. A method according to claim 17, wherein said doors have respective shafts, and operating respective electrical control switches through rotation of said shafts between door open and door closed positions and thereby electrically controlling said heatproducing means.

19. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a vertical wall structure with an outlet opening, comprising:

producing heat in said chamber to incinerate and vaporize the waste;

directing products of combustion and vapor from said first chamber through said opening into a second chamber within an afterburner duct of substantial length extending generally horizontally along said wall structure from said opening in contiguous and heat-exchange relation throughout most of its length to said first chamber; and

in said second chamber superheating the vapor and converting it into odorless gases.

20. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a wall, comprising:

producing heat in said chamber to incinerate and vaporize the waste;

directing products of combustion and vapor from said first chamber into a second chamber providing an afterburner duct of substantial length extending along said wall in contiguous and heat-exchange relation throughout most of its length to said first chamber;

in said second chamber superheating the vapor and converting it into odorless gases;

supporting solid waste within said first chamber in spaced generally horizontal alignment with a burner nozzle;

and enveloping the solid waste above and below by flame from the nozzle and thereby incinerating the waste.

21. A method according to claim 20, including collecting liquid waste separate from the solid waste, and directing flame heat into vaporizing relation to the liquid waste both thereabove and therebelow.

22. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a wall, comprising:

producing heat in said chamber to incinerate and vaporize the waste;

directing products of combustion and vapor from said first chamber into a second chamber providing an afterburner duct of substantial length extending along said wall in contiguous and heat-exchange relation throughout most of its length to said first chamber;

in said second chamber superheating the vapor and converting it into odorless gases;

supporting solid waste material at an elevation in said first chamber;

toilet and including a combustion and vaporizing first chamber having front, rear and side walls and receptive of waste to be incinerated, comprising:

producing heat in said chamber by flame from a burner extending through an opening in said rear wall to incinerate and vaporize the waste;

directing products of combustion and vapor from said first chamber through an exit opening in said front wall into a second chamber within an afterburner duct of substantial length extending along said side wall;

effecting heat transfer from said first chamber into said second chamber duct through said side wall;

in said second chamber superheating the vapor and converting it into substantially odorless gases;

and effecting exhausting suction with said second chamber duct at its end remote from said front wall opening. 

1. A method of waste disposal such as in an incinerator toilet, comprising: supporting solid waste material on a grate separate from and above liquid waste; and directing flame from an atmospheric burner operating on ordinary line or tank pressure mixed with atmospheric air toward one edge of the grate to envelop it and the solid material thereon both thereabove and therebelow and to evaporate the liquid waste by heat from the flame below the grate.
 2. A method according to claim 1, including providing the incinerating and vaporizing heat by substantially filling a grate enclosing combustion chamber with ''''soft'''' flame.
 3. A method according to claim 1, including cooling the odorless gases before exhausting them to atmosphere.
 4. A method according to claim 1, including mixing the odorless gases with cooling air and then exhausting the cool mixture to atmosphere.
 5. A method according to claim 1, including drawing said odorless gases and cooling air into a mixing chamber, and exhausting the mixture from the mixing chamber.
 6. A method according to claim 1, comprising issuing the flame from a nozzle horizontally aligned in spaced relation to said edge of the grate.
 7. A method according to claim 1, wherein said grate and burner are located within a fire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, and conducting the flame and products of combustion and vapor through an opening in said wall into a superheating chamber.
 8. A method according to claim 1, wherein said grate and burner are located within a fire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, conductinG the flame and products of combustion and vapor through an opening in said wall into a superheating chamber, and in said chamber controlling the temperature in a range of 950*F. to 1,200*F. for rendering the gases odorless to the human sense of smell before exhausting such gases to atmosphere.
 9. A method according to claim 1, wherein said grate and burner are located within a fire pot having a wall spaced beyond the opposite edge of the grate from the edge toward which the flame is directed, conducting the flame and products of combustion and vapor through an opening in said wall into a superheating chamber, and in said chamber maintaining a temperature on the order of 1,000*F.
 10. A method according to claim 1, wherein said grate and burner are operatively located in respect to a combustion and vaporizing first chamber having a wall and duct means of substantial length extending along said wall to provide a second chamber contiguous and in heat-exchange relation throughout most of its length to said first chamber, conducting products of combustion and vapor from the first chamber through said second chamber duct means, and in said second chamber superheating the products of combustion and vapor into odorless gases.
 11. A method according to claim 1, including deflecting part of the flame from the burner to more upwardly onto the grate and the material thereon, and deflecting part of the flame to move under the grate.
 12. A method according to claim 1, wherein said grate and burner are operatively located in respect to a combustion and vaporizing first chamber having a wall and duct means of substantial length extending along said wall and providing a second chamber contiguous and in heat-exchange relation throughout most of its length to said first chamber, conducting products of combustion and vapor from the first chamber through said second chamber duct means, in said second chamber superheating the products of combustion and vapor into odorless gases, and receiving the gases from the duct means in a mixing chamber and therein mixing the gases with cooling air before release to atmosphere.
 13. A method of waste disposal such as in an incinerating toilet, comprising: depositing solid waste material on a grate; collecting liquid waste in a receptacle below the grate; mixing air with fuel at ordinary line or tank pressure and producing flame thereby from an atmospheric burner; and directing flame from the burner toward one edge of the grate to envelop it and the material thereon both thereabove and therebelow with the flame and evaporating the liquid waste in the receptacle by heat from the flame below the grate.
 14. A method according to claim 13, including conducting products of combustion and vapor through a superheating chamber and therein converting the products of combustion and vapor to odorless gases, mixing the odorless gases with cooling air, and exhausting the cooled odorless gases to atmosphere.
 15. A method according to claim 13, including conducting products of combustion and vapor through a superheating chamber and therein converting the products of combustion and vapor to odorless gases, introducing heat in addition to heat derived from said burner into said chamber to accelerate superheating of the products of combustion and vapors, mixing the odorless gases with cooling air, and exhausting the cooled odorless gases to atmosphere.
 16. A method according to claim 13, including conducting products of combustion and vapors through a duct chamber and therein superheating and converting the same into odorless gases, and controlling said burner in response to temperature variance detected in respect to said duct chamber.
 17. A method of waste disposal such as in an incinerator toilet including an upwardly opening housing and an upwardly opening fire pot mounted within a lower portion of the housing, with means for directing material downwardly into the fire pot, comprising: moving a pair of fire door from a closed edge-to-edge position from between said fire pot and an upper portion of said housing into spaced apart position, depositing material to be incinerated into the fire pot with said fire doors in the spaced apart position; moving said fire doors into closed edge-to-edge position; operating heat-producing means to incinerate the material in the fire pot, and electrically controlling said heat-producing means by said fire doors individually to become inoperative when the doors are open and operative only both of when the doors are completely closed.
 18. A method according to claim 17, wherein said doors have respective shafts, and operating respective electrical control switches through rotation of said shafts between door open and door closed positions and thereby electrically controlling said heat-producing means.
 19. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a vertical wall structure with an outlet opening, comprising: producing heat in said chamber to incinerate and vaporize the waste; directing products of combustion and vapor from said first chamber through said opening into a second chamber within an afterburner duct of substantial length extending generally horizontally along said wall structure from said opening in contiguous and heat-exchange relation throughout most of its length to said first chamber; and in said second chamber superheating the vapor and converting it into odorless gases.
 20. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a wall, comprising: producing heat in said chamber to incinerate and vaporize the waste; directing products of combustion and vapor from said first chamber into a second chamber providing an afterburner duct of substantial length extending along said wall in contiguous and heat-exchange relation throughout most of its length to said first chamber; in said second chamber superheating the vapor and converting it into odorless gases; supporting solid waste within said first chamber in spaced generally horizontal alignment with a burner nozzle; and enveloping the solid waste above and below by flame from the nozzle and thereby incinerating the waste.
 21. A method according to claim 20, including collecting liquid waste separate from the solid waste, and directing flame heat into vaporizing relation to the liquid waste both thereabove and therebelow.
 22. A method of waste disposal such as in an incinerator toilet and including a combustion and vaporizing first chamber receptive of waste to be incinerated and having a wall, comprising: producing heat in said chamber to incinerate and vaporize the waste; directing products of combustion and vapor from said first chamber into a second chamber providing an afterburner duct of substantial length extending along said wall in contiguous and heat-exchange relation throughout most of its length to said first chamber; in said second chamber superheating the vapor and converting it into odorless gases; supporting solid waste material at an elevation in said first chamber; directing the flame from a gas burner nozzle aligned in spaced relation in a generally horizontal direction with the supported solid waste; and deflecting flame from the nozzle to move upwardly onto and under the supported solid waste material and thereby enveloping the same to effect incineration.
 23. A method of waste disposal such as an incinerator toilet and including a combustion and vaporizing first chamber having front, rear and side walls and receptive of waste to be incinerated, comprising: producing heat in said chamber by flame from a burner extending through an opening in said rear wall to incinerate and vaporize the waste; directing prodUcts of combustion and vapor from said first chamber through an exit opening in said front wall into a second chamber within an afterburner duct of substantial length extending along said side wall; effecting heat transfer from said first chamber into said second chamber duct through said side wall; in said second chamber superheating the vapor and converting it into substantially odorless gases; and effecting exhausting suction with said second chamber duct at its end remote from said front wall opening. 